diff --git a/pdf-umbenenner-adapter-out/src/main/java/de/gecheckt/pdf/umbenenner/adapter/out/configuration/ConfigurationLoadingException.java b/pdf-umbenenner-adapter-out/src/main/java/de/gecheckt/pdf/umbenenner/adapter/out/configuration/ConfigurationLoadingException.java
new file mode 100644
index 0000000..84783a1
--- /dev/null
+++ b/pdf-umbenenner-adapter-out/src/main/java/de/gecheckt/pdf/umbenenner/adapter/out/configuration/ConfigurationLoadingException.java
@@ -0,0 +1,38 @@
+package de.gecheckt.pdf.umbenenner.adapter.out.configuration;
+
+/**
+ * Exception thrown when configuration loading or parsing fails.
+ * <p>
+ * This exception covers all failures related to loading, reading, or parsing the configuration,
+ * including:
+ * <ul>
+ *   <li>I/O failures when reading the configuration file</li>
+ *   <li>Missing required properties</li>
+ *   <li>Invalid property values (e.g., unparseable integers, invalid URIs)</li>
+ * </ul>
+ * <p>
+ * This is a controlled failure mode that prevents processing from starting.
+ */
+public class ConfigurationLoadingException extends RuntimeException {
+
+    private static final long serialVersionUID = 1L;
+
+    /**
+     * Creates the exception with an error message.
+     *
+     * @param message the error message describing what failed during configuration loading
+     */
+    public ConfigurationLoadingException(String message) {
+        super(message);
+    }
+
+    /**
+     * Creates the exception with an error message and a cause.
+     *
+     * @param message the error message describing what failed during configuration loading
+     * @param cause   the underlying exception that caused the configuration failure
+     */
+    public ConfigurationLoadingException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}
diff --git a/pdf-umbenenner-adapter-out/src/main/java/de/gecheckt/pdf/umbenenner/adapter/out/configuration/PropertiesConfigurationPortAdapter.java b/pdf-umbenenner-adapter-out/src/main/java/de/gecheckt/pdf/umbenenner/adapter/out/configuration/PropertiesConfigurationPortAdapter.java
index bc8e3b8..7d1faa6 100644
--- a/pdf-umbenenner-adapter-out/src/main/java/de/gecheckt/pdf/umbenenner/adapter/out/configuration/PropertiesConfigurationPortAdapter.java
+++ b/pdf-umbenenner-adapter-out/src/main/java/de/gecheckt/pdf/umbenenner/adapter/out/configuration/PropertiesConfigurationPortAdapter.java
@@ -93,7 +93,7 @@ public class PropertiesConfigurationPortAdapter implements ConfigurationPort {
             String escapedContent = escapeBackslashes(content);
             props.load(new StringReader(escapedContent));
         } catch (IOException e) {
-            throw new RuntimeException("Failed to load configuration from " + configFilePath, e);
+            throw new ConfigurationLoadingException("Failed to load configuration from " + configFilePath, e);
         }
         return props;
     }
@@ -137,7 +137,7 @@ public class PropertiesConfigurationPortAdapter implements ConfigurationPort {
     private String getRequiredProperty(Properties props, String key) {
         String value = props.getProperty(key);
         if (value == null || value.isBlank()) {
-            throw new IllegalStateException("Required property missing: " + key);
+            throw new ConfigurationLoadingException("Required property missing: " + key);
         }
         return normalizePath(value.trim());
     }
@@ -161,7 +161,7 @@ public class PropertiesConfigurationPortAdapter implements ConfigurationPort {
         try {
             return Integer.parseInt(value.trim());
         } catch (NumberFormatException e) {
-            throw new IllegalStateException("Invalid integer value for property: " + value, e);
+            throw new ConfigurationLoadingException("Invalid integer value for property: " + value, e);
         }
     }
 
@@ -169,7 +169,7 @@ public class PropertiesConfigurationPortAdapter implements ConfigurationPort {
         try {
             return new URI(value.trim());
         } catch (URISyntaxException e) {
-            throw new IllegalStateException("Invalid URI value for property: " + value, e);
+            throw new ConfigurationLoadingException("Invalid URI value for property: " + value, e);
         }
     }
 }
\ No newline at end of file
diff --git a/pdf-umbenenner-adapter-out/src/test/java/de/gecheckt/pdf/umbenenner/adapter/out/configuration/PropertiesConfigurationPortAdapterTest.java b/pdf-umbenenner-adapter-out/src/test/java/de/gecheckt/pdf/umbenenner/adapter/out/configuration/PropertiesConfigurationPortAdapterTest.java
index 52ffcff..7ad2be6 100644
--- a/pdf-umbenenner-adapter-out/src/test/java/de/gecheckt/pdf/umbenenner/adapter/out/configuration/PropertiesConfigurationPortAdapterTest.java
+++ b/pdf-umbenenner-adapter-out/src/test/java/de/gecheckt/pdf/umbenenner/adapter/out/configuration/PropertiesConfigurationPortAdapterTest.java
@@ -127,13 +127,13 @@ class PropertiesConfigurationPortAdapterTest {
     }
 
     @Test
-    void loadConfiguration_throwsIllegalStateExceptionWhenRequiredPropertyMissing() throws Exception {
+    void loadConfiguration_throwsConfigurationLoadingExceptionWhenRequiredPropertyMissing() throws Exception {
         Path configFile = createConfigFile("missing-required.properties");
 
         PropertiesConfigurationPortAdapter adapter = new PropertiesConfigurationPortAdapter(emptyEnvLookup, configFile);
 
-        IllegalStateException exception = assertThrows(
-                IllegalStateException.class,
+        ConfigurationLoadingException exception = assertThrows(
+                ConfigurationLoadingException.class,
                 () -> adapter.loadConfiguration()
         );
 
@@ -142,13 +142,13 @@ class PropertiesConfigurationPortAdapterTest {
     }
 
     @Test
-    void loadConfiguration_throwsRuntimeExceptionWhenConfigFileNotFound() {
+    void loadConfiguration_throwsConfigurationLoadingExceptionWhenConfigFileNotFound() {
         Path nonExistentFile = tempDir.resolve("nonexistent.properties");
 
         PropertiesConfigurationPortAdapter adapter = new PropertiesConfigurationPortAdapter(emptyEnvLookup, nonExistentFile);
 
-        RuntimeException exception = assertThrows(
-                RuntimeException.class,
+        ConfigurationLoadingException exception = assertThrows(
+                ConfigurationLoadingException.class,
                 () -> adapter.loadConfiguration()
         );
 
@@ -206,7 +206,7 @@ class PropertiesConfigurationPortAdapterTest {
     }
 
     @Test
-    void loadConfiguration_throwsIllegalStateExceptionForInvalidIntegerValue() throws Exception {
+    void loadConfiguration_throwsConfigurationLoadingExceptionForInvalidIntegerValue() throws Exception {
         Path configFile = createInlineConfig(
                 "source.folder=/tmp/source\n" +
                 "target.folder=/tmp/target\n" +
@@ -223,8 +223,8 @@ class PropertiesConfigurationPortAdapterTest {
 
         PropertiesConfigurationPortAdapter adapter = new PropertiesConfigurationPortAdapter(emptyEnvLookup, configFile);
 
-        IllegalStateException exception = assertThrows(
-                IllegalStateException.class,
+        ConfigurationLoadingException exception = assertThrows(
+                ConfigurationLoadingException.class,
                 () -> adapter.loadConfiguration()
         );
 
@@ -279,6 +279,55 @@ class PropertiesConfigurationPortAdapterTest {
         assertEquals("INFO", config.logLevel(), "log.level should default to INFO");
     }
 
+    @Test
+    void allConfigurationFailuresAreClassifiedAsConfigurationLoadingException() throws Exception {
+        // Verify that file I/O failure uses ConfigurationLoadingException
+        Path nonExistentFile = tempDir.resolve("nonexistent.properties");
+        PropertiesConfigurationPortAdapter adapter1 = new PropertiesConfigurationPortAdapter(emptyEnvLookup, nonExistentFile);
+        assertThrows(ConfigurationLoadingException.class, () -> adapter1.loadConfiguration(),
+                "File I/O failure should throw ConfigurationLoadingException");
+
+        // Verify that missing required property uses ConfigurationLoadingException
+        Path missingPropFile = createConfigFile("missing-required.properties");
+        PropertiesConfigurationPortAdapter adapter2 = new PropertiesConfigurationPortAdapter(emptyEnvLookup, missingPropFile);
+        assertThrows(ConfigurationLoadingException.class, () -> adapter2.loadConfiguration(),
+                "Missing required property should throw ConfigurationLoadingException");
+
+        // Verify that invalid integer value uses ConfigurationLoadingException
+        Path invalidIntFile = createInlineConfig(
+                "source.folder=/tmp/source\n" +
+                "target.folder=/tmp/target\n" +
+                "sqlite.file=/tmp/db.sqlite\n" +
+                "api.baseUrl=https://api.example.com\n" +
+                "api.model=gpt-4\n" +
+                "api.timeoutSeconds=invalid\n" +
+                "max.retries.transient=2\n" +
+                "max.pages=100\n" +
+                "max.text.characters=50000\n" +
+                "prompt.template.file=/tmp/prompt.txt\n"
+        );
+        PropertiesConfigurationPortAdapter adapter3 = new PropertiesConfigurationPortAdapter(emptyEnvLookup, invalidIntFile);
+        assertThrows(ConfigurationLoadingException.class, () -> adapter3.loadConfiguration(),
+                "Invalid integer value should throw ConfigurationLoadingException");
+
+        // Verify that invalid URI value uses ConfigurationLoadingException
+        Path invalidUriFile = createInlineConfig(
+                "source.folder=/tmp/source\n" +
+                "target.folder=/tmp/target\n" +
+                "sqlite.file=/tmp/db.sqlite\n" +
+                "api.baseUrl=not a valid uri\n" +
+                "api.model=gpt-4\n" +
+                "api.timeoutSeconds=30\n" +
+                "max.retries.transient=2\n" +
+                "max.pages=100\n" +
+                "max.text.characters=50000\n" +
+                "prompt.template.file=/tmp/prompt.txt\n"
+        );
+        PropertiesConfigurationPortAdapter adapter4 = new PropertiesConfigurationPortAdapter(emptyEnvLookup, invalidUriFile);
+        assertThrows(ConfigurationLoadingException.class, () -> adapter4.loadConfiguration(),
+                "Invalid URI value should throw ConfigurationLoadingException");
+    }
+
     private Path createConfigFile(String resourceName) throws Exception {
         Path sourceResource = Path.of("src/test/resources", resourceName);
         Path targetConfigFile = tempDir.resolve("application.properties");
diff --git a/pdf-umbenenner-bootstrap/src/main/java/de/gecheckt/pdf/umbenenner/bootstrap/BootstrapRunner.java b/pdf-umbenenner-bootstrap/src/main/java/de/gecheckt/pdf/umbenenner/bootstrap/BootstrapRunner.java
index 1e6b564..a5c62b3 100644
--- a/pdf-umbenenner-bootstrap/src/main/java/de/gecheckt/pdf/umbenenner/bootstrap/BootstrapRunner.java
+++ b/pdf-umbenenner-bootstrap/src/main/java/de/gecheckt/pdf/umbenenner/bootstrap/BootstrapRunner.java
@@ -11,6 +11,7 @@ import org.apache.logging.log4j.Logger;
 import de.gecheckt.pdf.umbenenner.adapter.in.cli.SchedulerBatchCommand;
 import de.gecheckt.pdf.umbenenner.adapter.out.bootstrap.validation.InvalidStartConfigurationException;
 import de.gecheckt.pdf.umbenenner.adapter.out.bootstrap.validation.StartConfigurationValidator;
+import de.gecheckt.pdf.umbenenner.adapter.out.configuration.ConfigurationLoadingException;
 import de.gecheckt.pdf.umbenenner.adapter.out.configuration.PropertiesConfigurationPortAdapter;
 import de.gecheckt.pdf.umbenenner.adapter.out.fingerprint.Sha256FingerprintAdapter;
 import de.gecheckt.pdf.umbenenner.adapter.out.lock.FilesystemRunLockPortAdapter;
@@ -249,12 +250,12 @@ public class BootstrapRunner {
             BatchRunOutcome outcome = command.run(runContext);
             runContext.setEndInstant(Instant.now());
             return mapOutcomeToExitCode(outcome, runContext);
+        } catch (ConfigurationLoadingException e) {
+            LOG.error("Configuration loading failed: {}", e.getMessage());
+            return 1;
         } catch (InvalidStartConfigurationException e) {
             LOG.error("Configuration validation failed: {}", e.getMessage());
             return 1;
-        } catch (IllegalStateException e) {
-            LOG.error("Configuration loading failed: {}", e.getMessage());
-            return 1;
         } catch (DocumentPersistenceException e) {
             LOG.error("Persistence operation failed: {}", e.getMessage(), e);
             return 1;
diff --git a/pdf-umbenenner-bootstrap/src/test/java/de/gecheckt/pdf/umbenenner/bootstrap/BootstrapRunnerTest.java b/pdf-umbenenner-bootstrap/src/test/java/de/gecheckt/pdf/umbenenner/bootstrap/BootstrapRunnerTest.java
index 68fbce3..17694ea 100644
--- a/pdf-umbenenner-bootstrap/src/test/java/de/gecheckt/pdf/umbenenner/bootstrap/BootstrapRunnerTest.java
+++ b/pdf-umbenenner-bootstrap/src/test/java/de/gecheckt/pdf/umbenenner/bootstrap/BootstrapRunnerTest.java
@@ -3,6 +3,7 @@ package de.gecheckt.pdf.umbenenner.bootstrap;
 import de.gecheckt.pdf.umbenenner.adapter.in.cli.SchedulerBatchCommand;
 import de.gecheckt.pdf.umbenenner.adapter.out.bootstrap.validation.InvalidStartConfigurationException;
 import de.gecheckt.pdf.umbenenner.adapter.out.bootstrap.validation.StartConfigurationValidator;
+import de.gecheckt.pdf.umbenenner.adapter.out.configuration.ConfigurationLoadingException;
 import de.gecheckt.pdf.umbenenner.application.config.startup.StartConfiguration;
 import de.gecheckt.pdf.umbenenner.application.port.in.BatchRunOutcome;
 import de.gecheckt.pdf.umbenenner.application.port.in.BatchRunProcessingUseCase;
@@ -81,7 +82,7 @@ class BootstrapRunnerTest {
     @Test
     void run_returnsOneOnConfigurationLoadingFailure() {
         ConfigurationPort failingConfigPort = () -> {
-            throw new IllegalStateException("Simulated configuration loading failure");
+            throw new ConfigurationLoadingException("Simulated configuration loading failure");
         };
 
         BootstrapRunner runner = new BootstrapRunner(